The medial compartment osteoarthritis (OA) of knee joint has various surgical options such as high tibial osteotomy (HTO), hemiarthroplasty, and total knee arthroplasty. In the early stages of medial OA, there are no intra-articular deformities. Thus HTO, which is an extra-articular osteotomy, is recommended for the treatment of mild OA, but in moderate and severe medial OA, there are intra-articular deformities. HTO cannot correct these intra-articular deformities. Thus, an intra-articular osteotomy like the Tibial condylar valgus osteotomy (TCVO) is required in cases of moderate to severe medial OA knee. The contact area of the articular surface of the knee joint after TCVO is broader than it is after HTO in cases of moderate/severe OA. TCVO also improves the bony stability, eliminates the lateral thrust and surely corrects the alignment of the lower limb. To conclude, in cases of medial OA knee, the type of deformity must be evaluated and corrected accordingly. Intra-articular deformity must be corrected first. If the correction of varus and the mechanical axis is not enough, then extra-articular deformity must also be corrected, with a simultaneous or subsequent HTO.